@kamal, you should try the whole world 2 before returning to Boletaria (world 1), that's what I always do. Piercing attacks are effective against the miners there, so take note, 'cause anything else at this point is useless. Soul arrow will be very helpful against the bearbugs later in 2-2. Stay away from 4 and 5 (shrine and valley) it'll be just too tough for you, I usually leave 5 for last. Remember to NOT consume the soul of the Flamelurker (2-2 boss) which you need to give to the blacksmith located at the bottom level (through elevator) at the beginning of 2-1, that will enable you to open up important soul upgrades for weapons/shields.
I found world 5 to be one of the easiest. You just need Yurt's armor and some Soldier's Lotus and you're good. Enemies are very easy and there's only one threat in the entire world. (big diseased guys in 5-2)
World 4 is tough, but the bosses are soooo easy.